# WP-37 — Dev-switcher reset fix (scenario/role)

Status: done
Phase: 8 — platform/DX/showcase

## Why

The WP-33 dev switcher can't reset scenario/role back to `default`/`drafter` — it gets "stuck"
(e.g. on `slow`). Cause: `currentScenario()`/`currentRole()` read the URL `?scenario=`/`?role=`
param **before** sessionStorage, so once a param is in the address bar, `location.reload()` (same
URL) re-reads the stale value and overrides what the switcher just stored.

## Decisions

- Once the switcher is used, **sessionStorage is authoritative**; a leftover URL param must not
  win. Strip both dev params from the URL (`history.replaceState`) before reloading.
- Extract the URL rewrite as a **pure** `stripDevParams(href)` so it's unit-testable without
  touching `location.reload()`.

## Files

- `src/app/shared/infrastructure/dev-params.ts` (+ `dev-params.spec.ts`) — pure `stripDevParams`.
- `src/app/shared/ui/debug-state/debug-state.component.ts` — `switchRole`/`switchScenario` call
  `applyAndReload()` (replaceState with stripped URL, then reload).

## Acceptance criteria

- [x] Switching scenario/role to any value (incl. default/drafter) sticks after reload, even when
      a `?scenario=`/`?role=` param was in the URL.
- [x] `stripDevParams` removes both params, keeps other params + path/hash (spec).
- [x] `npm run ci` green.